Modified guanidine-containing polymers for biologic delivery

ABSTRACT

The subject invention provides materials and methods for intracellular deliver of molecules and/or therapeutic agents. The subject invention also provides methods for synthesizing polymeric systems and nanomaterials that enhance or assist the passage of molecules and/or therapeutic agents across biological membranes. The compound, polymer or nanoparticle of the subject invention comprises a modified guanidine moiety in a plurality of repeating units of a polymer or on the surface of a nanoparticle where the guanidine moiety comprises, for example, a carbamoyl or thiourea modification. The polymer or nanoparticle can be used in a cancer treatment formulation.

CROSS-REFERENCE TO A RELATED APPLICATION

This application is a continuation application of U.S. Ser. No.17/578,709, filed Jan. 19, 2022, which is incorporated herein byreference in its entirety.

GOVERNMENT SUPPORT

This invention was made with government support under DMR2105016 awardedby the National Science Foundation. The government has certain rights inthe invention.

BACKGROUND OF INVENTION

The design and synthesis of novel nanomaterials that enhance or assistthe passage of biologics, such as proteins, enzymes, and antibodies,across cellular membranes is of significant importance. Cell membranesare impermeable to most macromolecules. Many drug candidates fail toadvance clinically because they do not have the properties needed tocross biological membranes and reach their intracellular target.Additionally, poor pharmacokinetics, stability, and off-target effectslead to undesirable biological responses.

The cytosolic delivery of functional proteins could lead to an efficientand specific control of cellular processes for various diseasetreatments. Despite the success and promise of the first protein-baseddrugs, current protein-based therapeutics are mainly designed to targetthe extracellular receptors or secretory proteins due to the cellmembrane impermeability of most proteins.

Moreover, many standard laboratory techniques, such as immunostainingand gene editing, may require the intracellular accumulation of proteinsinside the cell. A major bottleneck in the advancement of biologicsdevelopment is due to the membrane impermeability of most proteins, anda lack of effective approaches to delivering proteins to intracellulartargets. Current commercially available materials face severelimitations for use, prompting the need for improved protein deliverysystems.

The covalent modification of proteins with membrane translocatingmoieties has been used, however, the risk of altered structure andfunction has led to significant focus on non-covalent methods. Lipids,peptides, and polymers all rely on relatively weak, non-covalentinteractions between the carrier and cargo. The synergisticinter-macromolecular ionic, hydrophobic, and hydrogen bond interactionsare essential to achieve proper complexation between the carrier andcargo, interaction with the cellular membrane, and release of theprotein inside the cell.

Numerous synthetic polymeric carriers have been developed for thetransport of proteins across cell membranes. Specifically,guanidine-rich polymers, relying on the key functional group ofcell-penetrating peptides, have gained attention. Due to the uniquedelocalized positive charge of guanidine, strong ionic and hydrophobicinteractions exist with the biomacromolecule cargo. Additionally, thecapability of bidentate hydrogen bond interactions assists in theassembly of complexes and cellular entry, especially when multipleguanidine units collectively interact with biomacromolecules in arelatively hydrophobic environment.

Despite the significant advantages, the high positive charge density ofguanidine-rich carriers, often results in poor complex stability due tonon-specific interactions with other macromolecules in physiologicalrelevant environments, resulting in poor outcomes. For example, the samepositive charge is often responsible for nonspecific binding with serumproteins, resulting in destabilization of protein/carrier complexes,alteration of cellular entry pathways, and diminishing overallintracellular entry efficiency. The hydrogen bond interactions inaqueous environments are also dramatically weakened as a large excess ofwater molecules strongly interacts with guanidine. Therefore,guanidine-based protein delivery systems perform poorly inserum-containing media.

Thus, there is a need to develop novel delivery materials, such asguanidine-rich compounds, carriers or polymers with improved efficacyand balanced hydrophobicity, which overcome the biological barrier.There is also a need to develop methods and approaches for modificationand synthesis of guanidine derivatives with improved efficacy.

BRIEF SUMMARY

The subject invention provides materials and methods for intracellulardelivery of molecules or therapeutic agents such as drugs, nucleicacids, and proteins. In one embodiment, the subject invention providesnanomaterials as molecule transporters or carriers for targeted deliveryof therapeutic agents into cells, preferably, cancer cells forinhibiting the growth of cancer cells and altering gene expression inthese cells.

In one embodiment, the nanomaterial of the subject invention comprises apolymer or nanoparticle that comprises a modified guanidine moiety in aplurality of repeating units of a polymer, or on the surface of ananoparticle.

In one embodiment, the modified guanidine moiety comprises a directconjugation of a planar carbamoyl group to guanidine, which decreasesthe pKa, leading to a decreased positive charge environment.Additionally, the hydrogen bonding moiety is extended by the carbamoylgroup. This reduced positive charge density, together with new hydrogenbond site, can lead to enhanced interactions between the carrier andcargo, and ultimately, improved protein delivery efficacy.

In a specific embodiment, the nanomaterial or polymer of the subjectinvention is a guanidylcarbamoyl or carbamoylguanidine derivative.Advantageously, the nanomaterials or polymers having such novelfunctional groups dramatically enhance intracellular biologics deliveryefficiency by improving serum stability, intracellular entry, andrelease of payloads. Thus, the nanomaterials and polymers of the subjectinvention function well in the absence or presence of serum, which issuperior compared to the existing cargo delivery materials.

For example, the coplanar phenyl group connected carbamoylguanidinederivative exhibits efficient delivery of proteins with various sizesand isoelectric points. The carbamoylguanidine derivative successfullydelivers apoptosis-inducing proteins even in a serum containing medium,as compared with most protein delivery systems that show a sharpefficiency decrease in the presence of serum.

In one embodiment, the subject invention provides a guanidinemodification to substantially improve functional protein deliveryefficiency. The decreased pKa of planar carbamoylguanidine increaseslocal hydrophobicity and hydrogen bond interactions, allowing theformation of stable protein complexes with improved complex stability ina serum-containing medium. The coplanarity of the phenyl group directlyintroduced to carbamoylguanidine plays a significant role in thecellular entry. The developed functional groups can be introduced tomany existing biologic delivery platforms to tackle the issuesassociated with therapeutic protein delivery.

BRIEF DESCRIPTION OF DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

FIG. 1 shows chemical structures of PNs containing various functionalgroups. CG: Carbamoylated (Cbm) Guanidine (G); Ph: Phenyl; Bz: Benzyl;PhPr: Phenylpropyl; and PhBu: Phenylbutyl.

FIG. 2 shows representative HD plots for Ph-CG (left) and Ph-CG/BSAcomplex (right), demonstrating formation of relatively monodispersenanoparticles after complexation.

FIGS. 3A-3C show the pKa determination. (3A) pH titration curves of PNswith KOH from pH 3 to 11. (3B-3C) Method for pKa determination of Ph-CG(3B) and random-Bz-G (3C). No value was determined using this method forrandom-Bz-G as there is only 1 maximum ΔpH.

FIG. 4 shows the relative fluorescent quenching of Rho-BSA complexedwith various PNs. Data represents the average of 3 independentexperiments. Errors bars were omitted for clarity of data.

FIG. 5 shows fractional saturation and fitting curves of PNs withRho-BSA.

FIGS. 6A-6B show stability of protein complexes of (6A) Ph-CG and (6B)random-Bz-G in PBS (left) and PBS containing 10% FBS (right). While bothPh-CG and random-Bz-G complexes show a relatively good stability in PBS,the complex stability in the serum-containing medium is substantiallydifferent. Ph-CG/protein complex exhibits high serum stability over theextended incubation time.

FIG. 7 shows the stability of Bz-CG/Rho-BSA complexes in PBS (left) andPBS containing 10% FBS (right).

FIG. 8 shows the cell viability inhibition of PNs at variousconcentrations.

FIG. 9 shows the median fluorescence intensity of HeLa cells treatedwith PN/R-PE complexes for 18 h. The percent R-PE positive cells arepresented at the right axis. The concentration of polymer and R-PE were10 μM and 15 nM, respectively. R-PE only was used as a negative control.PULSin was used as a positive control according to suggested guidelinesby the manufacturer. Data shown is the mean of three independentexperiments+/−standard deviation.

FIG. 10 shows flow cytometry histograms of Ph-CG mediated delivery ofEGFP, Rho-BSA and R-PE into HeLa, Mesenchymal Stem Cells (MSC), and Tcells. Almost complete cell populations show signals from R-PE within 3h of treatment. The concentrations of polymer, R-PE, EGFP, and Rho-BSAwere 10 μM, 15 nM, 60 nM, and 100 nM, respectively.

FIG. 11 shows the relative median fluorescence intensity of HeLa cellsin energy-independent conditions (ATP depletion and 4° C.) orpre-treated with various pharmacological endocytosis inhibitors followedby incubation with Ph-CG/R-PE complex for 1 h. The concentration ofpolymer and R-PE were 10 μM and 15 nM, respectively. Data shown is themean of three independent experiments+/−standard deviation. *p<0.05,**p<0.01, and ***p<0.001.

FIGS. 12A-12B show the viability of HeLa cells treated with Saporincomplexes with Ph-CG, random-Bz-G, and PULSin, respectively, at variousprotein concentrations in a serum-free (12A) and a serum-containingmedium (12B). The concentration of polymer was kept constant at 10 Freeproteins were used as controls. Data represents the mean of 3independent experiments+/−standard deviation.

FIGS. 13A-13B show the viability of HeLa cells treated with RNase onlyand Ph-CG/RNase A complexes at various RNase concentrations in aserum-free (13A) and a serum-containing medium (13B). The concentrationof polymer was kept constant at 10 μM. Data represents the mean of 3independent experiments+/−standard deviation.

FIGS. 14A-14D show confocal images of HeLa cells treated withFITC-BSA/Ph-CG (a: 1 h and b: 18 h) and random-Bz-G (c: 1 h and d: 18 h)complexes. Blue: nucleus, green: FITC-BSA, red: Lysotracker. PCC scoreswere indicated at the lower right conner. Scale bar: 20 μm.

FIGS. 15A-15C show confocal microscope images of HeLa cells incubatedwith PN and PULSin complexes of R-PE (15A), FITC-BSA (15B), and EGFP(15C). Concentrations of PN, R-PE, FITC-BSA and EGFP were 10 μM, 15 nM,100 nM and 100 nM, respectively.

FIGS. 16A-16B show mean fluorescence intensity (16A) and R-PE positivecells (16B) of HeLa cells treated with PN/R-PE complexes for 18 h. Theconcentration of R-PE was 2 nM, and polymers were screened from 1.25 to10 μM. Data shown is the mean of three independent experiments±standarddeviation.

FIG. 17 shows confocal images of HeLa cells treated with PN/EGFPcomplexes for 18 h. The concentration of PNs and EGFP was 10 μM and 80nM, respectively. Blue: nucleus, green: EGFP, red: ActinRed. Scale bar:20 μm.

DETAILED DISCLOSURE

The subject invention provides materials and methods for intracellulardeliver of molecules and/or therapeutic agents such as drugs, nucleicacids, peptides, dyes and proteins. The subject invention also providesmethods for the design and synthesis of polymeric systems andnanomaterials that enhance or assist the passage of therapeutic agentsacross biological membranes.

In one embodiment, the subject invention provides polymeric systemscomprising cell-penetrating peptide (CPP)-like moieties for transportingtherapeutic agents and/or biological molecules across biologicalmembranes. The polymeric systems can be used as molecular transportersor carriers that facilitate the internalization of therapeutic agentsand/or biological molecules by cells. Advantageously, the properties ofthe polymeric systems can be tuned by modulating the chemistry andarchitecture of the materials. Specifically, by retaining only the keyfeatures of CPPs necessary for sufficient internalization and deliveryof the cargo, CPP synthetic mimics (CPPMs) have improved propertiescompared to naturally occurring CPPs.

In one embodiment, the subject invention provides molecular transportersfor intracellularly delivering molecules and/or therapeutic agents suchas drugs, nucleic acids, peptides, dyes and proteins. In one embodiment,the molecular transporter comprises a material including, for example,organic/inorganic compounds, synthetic polymers, dendrimers, naturalpolymers, polysaccharides, proteins, peptides, antibodies, nucleicacids, metal organic framework, metallic nanoparticles, inorganicnanoparticles, and porous nanoparticles.

In one embodiment, the molecular transporters of the subject inventioncan be synthesized using ring-opening metathesis polymerization (ROMP).ROMP has great benefits over other polymerization techniques, whichinclude controlled polymer length, low polydispersity index (PDI) andeasy copolymer design.

In one embodiment, the molecular transporter comprises a compound,polymer or nanoparticle comprising one or more structures/functionalgroups selected from

wherein n≥1; W is O, S or Se; and Y and Y′ can be any functional group.Preferably, Y and Y′ are each independently selected from, for example,hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroalkyl,substituted heteroalkyl, heteroaryl, substituted heteroaryl, cycloalkyl,substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl,cycloalkenyl, substituted cycloalkenyl, alkenyl substituted alkenyl,alkoxy, substituted alkoxy, amino, alkynyl, hydroxyl, haloalkyl, acyl,alkylamino, arylamino and hydroxylalkyl.

In a preferred embodiment, Y′ is —NHR1, or —NR1R2; and n is 1-10,wherein R1 and R2 are each independently selected from, for example,hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroalkyl,substituted heteroalkyl, heteroaryl, substituted heteroaryl, cycloalkyl,substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl,cycloalkenyl, substituted cycloalkenyl, alkenyl substituted alkenyl,alkoxy, substituted alkoxy, alkynyl, hydroxyl, haloalkyl, acyl,alkylamino, arylamino and hydroxylalkyl.

In one embodiment, the molecular transporter comprises a compound,polymer or nanoparticle comprising one or more structures/functionalgroups selected from

in a plurality of repeating units of the compound or polymer, or on thesurface of a nanoparticle, wherein W is O, S, or Se; R and Y eachindependently can be any functional group. Preferably, R and Y are eachindependently selected from, for example, hydrogen, alkyl, substitutedalkyl, aryl, substituted aryl, heteroalkyl, substituted heteroalkyl,heteroaryl, substituted heteroaryl, cycloalkyl, substituted cycloalkyl,heterocycloalkyl, substituted heterocycloalkyl, cycloalkenyl,substituted cycloalkenyl, alkenyl substituted alkenyl, alkoxy,substituted alkoxy, alkynyl, haloalkyl, amino, acyl, alkylamino,acylamino and hydroxylalkyl.

In specific embodiments, the molecular transporter comprises a compound,polymer or nanoparticle comprising a guanidylcarbamoyl orcarbamoylguanidine group in a plurality of repeating units of a compoundor polymer, or on the surface of a nanoparticle.

In one embodiment, the compound or polymer of the subject invention is aguanidylcarbamoyl derivative (e.g., GuanidinylCarbamoyl Benzene (GCB))or a carbamoylguanidine derivative (e.g., CarbamoylGuanidinyl Pyrimidine(CGP) and CarbamoylGuanidinyl Benzene (CGB)). In specific embodiments,the guanidylcarbamoyl derivative comprises one or more guanidylcarbamoylgroups. The carbamoylguanidine derivative comprises one or morecarbamoylguanidine groups.

In certain embodiments, the polymer or compound of the subject inventioncomprises a direct conjugation of planar carbamoyl (Cbm) group toguanidine. Advantageously, such conjugation decreases the pKa ofguanidine, leading to decreased positive charge density in physiologicalenvironments. This reduced charge density is expected to increase thelocal hydrophobicity, which significantly enhances the efficiency ofhydrogen bond interactions in combination with the increased number(i.e., tridentate) of hydrogen bond sites of the carbamoylguanidinyl orguanidinylcarbamoyl group.

In a specific embodiment, the guanidylcarbamoyl group has a structure of

wherein R can be any functional group. Preferably, R is selected from,for example, hydrogen, alkyl, substituted alkyl, aryl, substituted aryl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl,substituted heterocycloalkyl, cycloalkenyl, substituted cycloalkenyl,alkenyl substituted alkenyl, alkoxy, substituted alkoxy, alkynyl,haloalkyl, amino, acyl, alkylamino, arylamino and hydroxylalkyl.

In a specific embodiment, the carbamoylguanidine group has a structure

wherein Y can be any functional group. Preferably, Y is selected from,for example, hydrogen, alkyl, substituted alkyl, aryl, substituted aryl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl,substituted heterocycloalkyl, cycloalkenyl, substituted cycloalkenyl,alkenyl substituted alkenyl, alkoxy, substituted alkoxy, alkynyl, amino,haloalkyl, acyl, alkylamino, arylamino and hydroxylalkyl.

In one embodiment, the molecular transporter of the subject inventioncomprises a conjugated polymer (CP). Biodegradable CPs can be formed byintroducing flexible degradable functional groups along the backbone ofthe CP that can be used for quantitative labeling of mitochondria.Cellular interaction and internalization of CPs are dependent on thechemical structures of both the backbone and side chains of the CPs. CPswith guanidine units (G-CPs), as disclosed in Moon et al. U.S. Pat. Nos.9,676,886; 9,757,410; and 10,688,189, which are incorporated herein byreference, enter live cells quickly through the cell membrane.

In specific embodiments, the conjugated polymer comprisespoly(phenyleneethynylene), poly(phenylenevinylene), poly(phenylene),poly(fluoreine), polythiophene, or any p-electron conjugated polymers.

In embodiments of the invention, the polymer need not be a conjugatedpolymer, which is generally ridged, but can be a non-conjugated polymerthat has a flexible backbone. In embodiments of the invention, thepolymer can have flexible side chains that enhance the water solubilityof the polymer. Synthetic and natural polymers that can be employed canbe, but are not limited to, amine functionalized polymethacrylates andpolyacrylates, branched and linear polyehtyleneimines, polyamidoamine,amine functionalized dendrimers, poly-L-lysine, chitosan, aminefunctionalized dextran, amine functionalized alginates, aminefunctionalized heparin, and amine functionalized oligo orpolysaccharide.

In embodiments of the invention, nanoparticles are used for efficientintracellular delivery and labeling after modulating surface propertiesto enhance their initial interaction following entry. The nanoparticlescan be those that are metal oxides, metal carbides, metal nitrides,metals, diamond, or any other type of nanoparticle. The polymer can bein the form of a soluble polymer or can be a nanoparticle where thefunctional groups are of sufficient concentration at the nanoparticlesurface to yield a nanoparticle that is decorated with one or moreguanidylcarbamoyl and/or carbamoylguanidine groups. The nanoparticlescan be of a single structure or a core-shell particle. The particles caninherently have surface functionality that react with guanidylcarbamoyland/or carbamoylguanidine groups. The particle surface can befunctionalized by reaction with an agent, for example, a silane couplingagent, such as, but not limited to, 3-aminopropyltrimethoxy silane, orthiol or disulfide containing alkyls with hydroxyl or amine groups forfunctionalization of metal nanoparticles.

In one embodiment, the compound/polymer of the subject inventioncomprises a structure selected from

wherein n≥1; W is S, O, or Se; Q, Y and Y′ can be any functional group.Preferably, n is 1-10; and Q, Y and Y′ are each independently selectedfrom, for example, hydrogen, alkyl, substituted alkyl, aryl, substitutedaryl, heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl,substituted heterocycloalkyl, cycloalkenyl, substituted cycloalkenyl,alkenyl substituted alkenyl, alkynyl, haloalkyl, alkoxy, substitutedalkoxy, amino, acyl, alkylamino, arylamino and hydroxylalkyl. Morepreferably, Y′ is —NHR1, or —NR1R2, wherein R1 and R2 are eachindependently selected from, for example, hydrogen, alkyl, substitutedalkyl, aryl, substituted aryl, heteroalkyl, substituted heteroalkyl,heteroaryl, substituted heteroaryl, cycloalkyl, substituted cycloalkyl,heterocycloalkyl, substituted heterocycloalkyl, cycloalkenyl,substituted cycloalkenyl, alkenyl substituted alkenyl, alkoxy,substituted alkoxy, alkynyl, hydroxyl, haloalkyl, acyl, alkylamino,arylamino and hydroxylalkyl.

In a preferred embodiment, the functional groups Y, Y′ and R show acoplanarity with the Cbm group and/or guanidine. For example, Y, Y′ andR may each be independently selected from

wherein each Z is independently C or N.

In a specific embodiment, the compound/polymer of the subject inventioncomprises a structure selected from

In a specific embodiment, the compound of the subject inventioncomprises a structure of

wherein Q can be any functional group. Preferably, Q, is selected from,for example, hydrogen, alkyl, substituted alkyl, aryl, substituted aryl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl,substituted heterocycloalkyl, cycloalkenyl, substituted cycloalkenyl,alkenyl substituted alkenyl, alkoxy, substituted alkoxy, alkynyl,haloalkyl, acyl, alkylamino, arylamino and hydroxylalkyl.

In specific embodiments, the compound of the subject invention has astructure of

wherein each Z is C or N; and R′ can be any functional group.Preferably, R′ is selected from, for example, hydrogen, halogen, alkyl,substituted alkyl, aryl, substituted aryl, heteroalkyl, substitutedheteroalkyl, heteroaryl, substituted heteroaryl, cycloalkyl, substitutedcycloalkyl, heterocycloalkyl, substituted heterocycloalkyl,cycloalkenyl, substituted cycloalkenyl, hydroxyl, alkoxy, substitutedalkoxy, alkenyl substituted alkenyl, alkynyl, haloalkyl, amino, acyl,alkylamino, arylamino and hydroxylalkyl.

In one embodiment, the compound/polymer of the subject inventioncomprises one or more structures/functional groups selected from

wherein W is S, O, or Se; Z is N or C; X is a linker; and R′ is selectedfrom, for example, hydrogen, halogen, alkyl, substituted alkyl, aryl,substituted aryl, heteroalkyl, substituted heteroalkyl, heteroaryl,substituted heteroaryl, cycloalkyl, substituted cycloalkyl,heterocycloalkyl, substituted heterocycloalkyl, cycloalkenyl,substituted cycloalkenyl, alkenyl substituted alkenyl, amino, hydroxyl,alkoxy, substituted alkoxy, alkynyl, haloalkyl, acyl, alkylamino,arylamino and hydroxylalkyl. In a specific embodiment, the linker may bealkylene, alkoxylene or heteroalkylene, preferrably, a short (e.g.,C1-C10) alkylene, alkoxylene or heteroalkylene. In a specificembodiment, the linker is ethylene oxide with different lengths, e.g.,—(CH₂CH₂O-)n-, wherein n≥1, preferrably, n=1-100.

In one embodiment, the polymeric system/nanocarrier of the subjectinvention comprises

wherein

represents, for example, the backbone of a compound or polymer,polysaccharide, protein, peptide, antibody, nucleic acid, metal organicframework or a nanoparticle; n≥1; W is S, O or Se; X, Y and Y′ can beany functional group. Preferably, n is 1-10; X is a linker; and Y and Y′are each independently selected from, for example, hydrogen, alkyl,substituted alkyl, aryl, substituted aryl, heteroalkyl, substitutedheteroalkyl, heteroaryl, substituted heteroaryl, cycloalkyl, substitutedcycloalkyl, heterocycloalkyl, substituted heterocycloalkyl,cycloalkenyl, substituted cycloalkenyl, alkenyl substituted alkenyl,alkynyl, alkoxy, substituted alkoxy, hydroxyl, haloalkyl, amino, acyl,alkylamino, arylamino and hydroxylalkyl. More preferably, Y′ is —NHR1,or —NR1R2, wherein R1 and R2 are each independently selected from, forexample, hydrogen, alkyl, substituted alkyl, aryl, substituted aryl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl,substituted heterocycloalkyl, cycloalkenyl, substituted cycloalkenyl,alkenyl substituted alkenyl, alkoxy, substituted alkoxy, alkynyl,hydroxyl, haloalkyl, acyl, alkylamino, arylamino and hydroxylalkyl.

In a specific embodiment, the linker may be alkylene, alkoxylene orheteroalkylene, preferrably, a short (e.g., C1-C10) alkylene, alkoxyleneor heteroalkylene. In a specific embodiment, the linker is ethyleneoxide with different lengths, e.g., —(CH₂CH₂O-)n-, wherein n≥1,preferrably, n=1-100.

In certain embodiments, the compound/polymer/nanoparticle of the subjectinvention comprises

wherein

represents, for example, the backbone of a compound or polymer,polysaccharide, protein, peptide, antibody, nucleic acid, metal organicframework or a nanoparticle; Z is C or N; X is a linker; and R′ can beany functional group. Preferably, R′ is selected from, for example,hydrogen, halogen, alkyl, substituted alkyl, aryl, substituted aryl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl,substituted heterocycloalkyl, cycloalkenyl, substituted cycloalkenyl,alkenyl substituted alkenyl, alkynyl, alkoxy, substituted alkoxy, amino,haloalkyl, hydroxyl, acyl, alkylamino, arylamino and hydroxylalkyl.

In a specific embodiment, the linker may be alkylene, alkoxylene orheteroalkylene, preferrably, a short (e.g., C1-C10) alkylene, alkoxyleneor heteroalkylene. In a specific embodiment, the linker is ethyleneoxide with different lengths, e.g., —(CH₂CH₂O-)n-, wherein n≥1,preferrably, n=1-100.

In certain embodiments, Y and Y′ are each independently carbon or otheratoms that result in a pKa higher than 7, the functional group of Y andY′ may be protonated.

In one embodiment, the polymeric system according to the subjectinvention comprises a compound or polymer comprising one or moreguanidylcarbamoyl and/or carbamoylguanidine groups on a plurality ofrepeating units of the compound or polymer. Advantageously, the directconjugation of planar carbamoyl group to guanidine in the compounds andpolymers of the subject invention decrease the pKa, leading to adecreased positive charge environment. Additionally, the hydrogenbonding moiety is extended by the carbamoyl group. This reduced positivecharge density, together with new hydrogen bond site, leads to enhancedinteractions between the carrier and cargo, and ultimately, improvedprotein delivery efficacy.

In one embodiment, the compound/polymer/nanomaterial of the subjectinvention comprises one or more polynorbornenes (PNs) in the polymericsystem.

In one embodiment, the polymer of the subject invention comprises apolymer chain that comprises one or more types of constituent units orrepeating units. Preferably, the repeating unit or monomer comprises astructure selected from

wherein W is O, S or Se; n≥1; and Y and Y′ are each independentlyselected from, for example, hydrogen, alkyl, substituted alkyl, aryl,substituted aryl, heteroalkyl, substituted heteroalkyl, heteroaryl,substituted heteroaryl, cycloalkyl, substituted cycloalkyl,heterocycloalkyl, substituted heterocycloalkyl, cycloalkenyl,substituted cycloalkenyl, alkenyl substituted alkenyl, alkoxy,substituted alkoxy, hydroxyl, alkynyl, haloalkyl, acyl, amino,alkylamino, arylamino and hydroxylalkyl.

In a preferred embodiment, Y′ is —NHR1, or —NR1R2, wherein R1 and R2 areeach independently selected from, for example, hydrogen, alkyl,substituted alkyl, aryl, substituted aryl, heteroalkyl, substitutedheteroalkyl, heteroaryl, substituted heteroaryl, cycloalkyl, substitutedcycloalkyl, heterocycloalkyl, substituted heterocycloalkyl,cycloalkenyl, substituted cycloalkenyl, alkenyl substituted alkenyl,alkoxy, substituted alkoxy, alkynyl, hydroxyl, haloalkyl, acyl,alkylamino, arylamino and hydroxylalkyl.

In some embodiments, Y and Y′ are each independently selected fromN-alkylamino; N-arylamino; N-(alkylaryl)amino; N-(aryalkyl)amino; N,N-dialkylamin; N, N-diarylamino; N, N-di(alkylaryl)amino; N,N-di(aryalkylamino); N-alkyl, N-arylamino; N-alkyl, N-(alkylaryl)amino;N-alkyl, N-(arylalkyl)amino; N-aryl, N-(alkylaryl)amino; N-aryl,N-(arylalkyl)amino; unsubstituted or substituted morpholine;unsubstituted or substituted pyrolidine; unsubstituted or substitutedpyrrole; unsubstituted or substituted piperidine; unsubstituted orsubstituted ethyleneimine; unsubstituted or substituted indole;unsubstituted or substituted isoindole; unsubstituted or substitutedcarbazole; imidazole or substituted imidazole; purine or substitutedpurine; aminoethanol; amino terminal polyethylene oxide, substituted orunsubstituted alky carbamate, substituted or unsubstituted arylcarbamate, substituted or unsubstituted alkylaryl carbamate andsubstituted or unsubstituted aryalkyl carbamate. In a specificembodiment, Y and Y′ are each independently selected from phenyl (Ph),benzyl (Bz), phenylpropyl (PhPr), phenylbutyl (PhBu), hexylamine (HA),benzylamine (BA), and aminoethoxyethanol (AEE).

In specific embodiments, the monomer comprises or has a structureselected from:

wherein p≥0.

In a specific embodiment, the monomer comprises or has a structure of

In one embodiment, the polymer is a homopolymer that comprises astructure selected from

wherein m≥2; n≥1; W is S, O or Se; and Y and Y′ are each independentlyselected from, for example, hydrogen, alkyl, substituted alkyl, aryl,substituted aryl, heteroalkyl, substituted heteroalkyl, heteroaryl,substituted heteroaryl, cycloalkyl, substituted cycloalkyl,heterocycloalkyl, substituted heterocycloalkyl, cycloalkenyl, andsubstituted cycloalkenyl, alkenyl and substituted alkenyl, alkynyl,alkoxy, substituted alkoxy, hydroxyl, haloalkyl, acyl, amino,alkylamino, arylamino and hydroxylalkyl.

In one embodiment, n is 2-100, 2-90, 2-80, 2-70, 2-60, 2-50, 2-40, 2-30,2-20, or 2-10. In one embodiment, p is 0-20. Preferably, p is 0-10. Morepreferably, p is 0-5.

In one embodiment, the polymer is a homopolymer that comprises astructure selected from:

wherein p≥0; and m≥2.

In a specific embodiment, the polymer is a homopolymer that comprisesthe structure of

wherein m≥2.

In some embodiments, the polymer of the subject invention furthercomprises a functional group (e.g., phenyl) at the end of the polymerchain. Such polymer may have a structure of, for example,

wherein m≥2.

In one embodiment, the polymer is a copolymer comprises a polymer chainthat comprises two or more types of constituent units or repeatingunits. In a further embodiment, the copolymer may be a bipolymer that isobtained by copolymerization of two monomer species, a terpolymer thatis obtained by copolymerization of three monomer species, or aquaterpolymer that is obtained by copolymerization of four monomerspecies.

In one embodiment, the polymer of the subject invention furthercomprises one or more repeating units or monomer species selected from

In one embodiment, the copolymer is an alternating copolymer, periodiccopolymer, random copolymer or block copolymer. An alternating copolymeris a copolymer comprising two species of monomeric units distributed inalternating sequence, for example, -ABABABAB- or -(AB)n-. A randomcopolymer is a copolymer comprising two or more types of monomer specieswith each monomer residue located randomly in the polymer molecule, forexample, -AAAABBBABBA-, or -AAAABCBBCBACCBC-. A periodic copolymer acopolymer comprising two or more types of monomer species and has unitsarranged in a repeating sequence, for example, -(ABABBAAAABBB)n-, or-(AABCBAABBBCCAB)n-. A block copolymer is a copolymer comprising two ormore blocks of different homopolymers chemically attached to each other,e.g., by covalent bonds. For example, a block copolymer having repeatingunits A and B may be arranged as -AAAAABBBBB- or -AAAAABBBBBAAAAA-.

In one embodiment, the polymer is a block copolymer that inducesnanostructure formation, e.g., when in aqueous environment, forming amicelle type nanostructure. Advantageously, the polymers may be used toencapsulate drugs/small molecules. Additionally, these copolymers may beused to complex macromolecules such as proteins where the blockstructure may enhance the nanoparticle formation.

In one embodiment, the polymer is a block copolymer comprising a polymerchain that comprises one or more blocks of the homopolymer of thesubject invention, and the polymer chain further comprises one or moreblocks of homopolymer comprising monomer species selected from

In one embodiment, the homopolymer and/or copolymer of the subjectinvention comprises one or more boronic acid moieties. Boronic acidshave strong binding affinity to biomolecules containing vicinal diols,such as sialic acid. Specifically, boronic acids can target lowabundance biomolecules in glucose rich environments. Increased levels ofsialic acid have been observed in many cancer cell lines. Thus, suchcopolymer containing boronic acid moieties may be used as a targetedtherapy for cancer treatments. Specifically, ligand affinity andspecificity can be tuned by functionalizing boronic acid probes.Functionalization of phenylboronic acid derivatives changes the pKa ofthe boronic acid probes and the stability of tumor tissue in the acidicmicroenvironment.

In one embodiment, the subject invention provides a nanomaterial thatcomprises a polymer of the subject invention conjugated to the surfaceof a nanoparticle. The nanoparticle comprises one or more materialsselected from silica, alumina, titania, zinc oxide, tin oxide, silveroxide, cuprous oxide, cupric oxide, ceria, vanadium oxide zirconia,molybdenum, tungsten oxide, barium oxide, calcium oxide, iron oxide, andnickel oxide.

In one embodiment, the subject invention also provides a therapeuticformulation comprising the polymer or nanoparticle of the subjectinvention and a pharmaceutically acceptable carrier, wherein thetherapeutic formulation further comprises one or more therapeuticagents, wherein one or more therapeutic agents are encapsulated by, orotherwise associated with, the compound/polymer/nanomaterials of thesubject invention.

In one embodiment, the therapeutic formulation of the subject inventioncomprises a mixture/complex of the polymer or nanoparticle of thesubject invention and one or more therapeutic agents, wherein thepolymer or nanoparticle is mixed with the therapeutic agent at aconcentration ratio ranging, for example, from about 1:1 to about1000:1, from about 1:1 to about 900:1, from about 1:1 to about 800:1,from about 1:1 to about 700:1, from about 1:1 to about 600:1, from about1:1 to about 500:1, from about 1:1 to about 400:1, from about 1:1 toabout 300:1, from about 1:1 to about 200:1, from about 1:1 to about100:1, from about 1:1 to about 90:1, from about 1:1 to about 80:1, fromabout 1:1 to about 70:1, from about 1:1 to about 60:1, from about 1:1 toabout 50:1, from about 1:1 to about 40:1, from about 1:1 to about 30:1,from about 1:1 to about 20:1, or from about 1:1 to about 10:1.

“Pharmaceutically acceptable carrier” refers to a diluent, adjuvant, orexcipient with which the one or more active agents disclosed herein canbe formulated. Typically, a “pharmaceutically acceptable carrier” is asubstance that is non-toxic, biologically tolerable, and otherwisebiologically suitable for administration to a subject, such as an inertsubstance, added to a pharmacological composition or otherwise used as adiluent, adjuvant, or excipient to facilitate administration of thecomposition disclosed herein and that is compatible therewith. Examplesof carriers suitable for use in the pharmaceutical compositions areknown in the art and such embodiments are within the purview of theinvention. The pharmaceutically acceptable carriers and excipientsinclude, but are not limited to, aqueous vehicles, water-misciblevehicles, non-aqueous vehicles, stabilizers, solubility enhancers,isotonic agents, buffering agents, suspending and dispersing agents,wetting or emulsifying agents, complexing agents, sequestering orchelating agents, cryoprotectants, lyoprotectants, thickening agents, pHadjusting agents, and inert gases. Other suitable excipients or carriersinclude, but are not limited to, dextran, glucose, maltose, sorbitol,xylitol, fructose, sucrose, and trehalose.

In one embodiment, the subject invention further provides methods fortreating a cancer, the method comprising administering, to a subject inneed of such treatment, an effective amount of the therapeuticformulation of the subject invention.

The term “subject” or “patient,” as used herein, describes an organism,including mammals such as primates. Mammalian species that can benefitfrom the disclosed methods of treatment include, but are not limited to,apes, chimpanzees, orangutans, humans, and monkeys; domesticated animalssuch as dogs, and cats; live stocks such as horses, cattle, pigs, sheep,goats, and chickens; and other animals such as mice, rats, guinea pigs,and hamsters.

The terms “treatment” or any grammatical variation thereof (e.g., treat,treating, etc.), as used herein, includes but is not limited to, theapplication or administration to a subject (or application oradministration to a cell or tissue from a subject) with the purpose ofdelaying, slowing, stabilizing, curing, healing, alleviating, relieving,altering, remedying, less worsening, ameliorating, improving, oraffecting the disease or condition, a symptom of the disease orcondition, or the risk of (or susceptibility to) the disease orcondition. The term “treating” refers to any indication of success inthe treatment or amelioration of a pathology or condition, including anyobjective or subjective parameter such as abatement; remission;lessening of the rate of worsening; lessening severity of the disease;stabilization, diminishing of symptoms or making the pathology orcondition more tolerable to the subject; or improving a subject'sphysical or mental well-being.

In one embodiment, the subject invention provides methods for targeteddelivery of a compound or molecule, including therapeutic agents (e.g.,drugs, antibodies, DNAs, RNAs such as siRNAs and miRNAs, peptides, andproteins), into cells, preferably cancer cells and epithelium cells, themethod comprising contacting the cells with the polymeric system ortherapeutic formulation of the subject invention.

In one embodiment, the subject invention provides methods for targeteddelivery of a therapeutic agent into cells, preferably cancer cells andepithelium cells, the method comprising contacting the cells with thepolymer of the subject invention and the therapeutic agent.

In one embodiment, the subject invention provides methods for targeteddelivery of a compound or molecule, including therapeutic agents (e.g.,drugs, antibodies, DNAs, RNAs such as siRNAs and miRNAs, peptides, andproteins), into the nuclei of cells, preferably cancer cells andepithelium cells, the method comprising contacting the cells with thepolymeric system or therapeutic formulation of the subject invention.

In one embodiment, the subject invention provides methods for targeteddelivery of a therapeutic agent into the nuclei of cells, preferablycancer cells and epithelium cells, the method comprising contacting thecells with the polymer of the subject invention and the therapeuticagent.

In one embodiment, the subject invention provides methods fortransporting a compound or molecule, including therapeutic agents (e.g.,drugs, antibodies, DNAs, RNAs such as siRNAs and miRNAs, peptides, andproteins), across a biological membrane, the method comprisingcontacting the biological membrane with the polymeric system orformulation of the subject invention. The biological membrane may be,for example, cell membranes, organelle membranes, mucous membranes,basement membranes, and serous membranes.

In one embodiment, the subject invention provides methods fortransporting a therapeutic agent across a biological membrane, themethod comprising contacting the biological membrane with the polymer ofthe subject invention and the therapeutic agent.

In one embodiment, the subject invention further provides methods foraltering/modulating gene expression in a cell, preferably a cancer cellor an epithelium cell, the method comprising contacting the cell withthe polymeric system or therapeutic formulation of the subjectinvention. Altering/modulating gene expression in a cell includesinhibiting or promoting gene expression in the cell.

In one embodiment, the subject invention further provides methods foraltering/modulating gene expression in a cell, preferably a cancer cellor an epithelium cell, the method comprising contacting the cell withthe polymer of the subject invention and the therapeutic agent.

In one embodiment, the subject invention further provides methods forinhibiting gene expression in a cell, preferably a cancer cell or anepithelium cell, the method comprising contacting the cell with thepolymeric system or therapeutic formulation of the subject invention.

As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. Further, to the extent that the terms “including,”“includes,” “having,” “has,” “with,” or variants thereof are used ineither the detailed description and/or the claims, such terms areintended to be inclusive in a manner similar to the term “comprising.”The transitional terms/phrases (and any grammatical variations thereof),such as “comprising,” “comprises,” and “comprise,” can be usedinterchangeably.

The transitional term “comprising,” “comprises,” or “comprise” isinclusive or open-ended and does not exclude additional, unrecitedelements or method steps. By contrast, the transitional phrase“consisting of” excludes any element, step, or ingredient not specifiedin the claim. The phrases “consisting” or “consists essentially of”indicate that the claim encompasses embodiments containing the specifiedmaterials or steps and those that do not materially affect the basic andnovel characteristic(s) of the claim. Use of the term “comprising”contemplates other embodiments that “consist” or “consisting essentiallyof” the recited component(s).

The term “about” or “approximately” means within an acceptable errorrange for the particular value as determined by one of ordinary skill inthe art, which will depend in part on how the value is measured ordetermined, i.e., the limitations of the measurement system. Forexample, “about” can mean within 1 or more than 1 standard deviation,per the practice in the art. Alternatively, “about” can mean a range ofup to 0-20%, 0 to 10%, 0 to 5%, or up to 1% of a given value.Alternatively, particularly with respect to biological systems orprocesses, the term can mean within an order of magnitude, preferablywithin 5-fold, and more preferably within 2-fold, of a value. Whereparticular values are described in the application and claims, unlessotherwise stated the term “about” meaning within an acceptable errorrange for the particular value should be assumed. In the context ofcompositions containing amounts of concentrations of ingredients wherethe term “about” is used, these values include a variation (error range)of 0-10% around the value (X±10%).

The recitation of a listing of chemical groups in any definition of avariable herein includes definitions of that variable as any singlegroup or combination of listed groups. The recitation of an embodimentfor a variable or aspect herein includes that embodiment as any singleembodiment or in combination with any other embodiments or portionsthereof.

EXAMPLES Methods and Materials

Materials

Reagents and solvents were purchased from Fisher Scientific and usedwithout further purification. Deuterated solvents were purchased fromCambridge Isotope Laboratories. The number average molecular weight(Mn), weight average molecular weight (Mw), and polydispersity index(PDI=Mw/Mn) of Polymers were determined by gel permeation chromatography(GPC) against polystyrene standards using a Shimadzu high performanceliquid chromatography (HPLC) system fitted with PLgel 5 MIXED-D columnsand SPD-20A ultraviolet-visible (UV-vis) detector at a flow rate of 1.0mL/min. Samples for GPC, small amount of dry polymer was dissolved with1 mL of HPLC grade THF and then filtered through a 0.45 umpolytetrafluoroethylene (PTFE) syringe filter prior injection. UV-visspectra were recorded using a Varian Cary 50 Bio spectrophotometer.Nuclear magnetic resonance (NMR) spectra were recorded on a 400 MHzAvance Bruker NMR spectrometer. Hydrodynamic diameters were obtainedusing a LM10 HS (NanoSight, Amesbury, United Kingdom), equipped with asCMOS camera, a sample chamber with Viton fluoroelastomer O-ring, and a488 nm blue laser. Zeta potentials were determined by using a ZetasizerNano-Zs (Zen 3600, Malvern Instruments) using a Zeta dip cell.Fluorescence emission spectra were recorded using a FluoroLog-3Spectrofluorometer (Horiba). Absorbance measurements were recorded on aTecan Infinite M1000 Pro microplate well reader at 570 nm. Flowcytometry experiments were done using a BD FACSCelesta system and datawas analyzed using FlowJo VX. Confocal laser scanning microscopy imageswere collected using a Nikon A1R microscope with a 60× objective withoil immersion. DAPI, FITC, and TRITC channels were used for fluorescencedetection.

General Methodology of Ring Opening Polymerization (ROMP) MonomerSynthesis:

Described is the synthesis of 3 new monomers containingN-Boc-N-(R)-Guanidyl Carbamoyl derivates that were obtained in threesteps (Scheme 1). First, Ethylenediamine is monoprotected using Boc₂Ochemistry. Second, Diels Alder adduct(exo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride) reactswith the N-Boc-ethylenediamine and then, deprotected withtrifluoroacetic acid in methylene chloride. N,N-di-Boc-Guanidinesderivates are obtained using N,N′-Di-Boc-pyrazole-1-carboxamidine or1,3-Bis(tert-butoxycarbonyl)-2-methyl-2-thiopseudourea with Mercury (II)Chloride. The last step is the reaction of the N,N-di-Boc-guanylatesubtract with the corresponding unprotected amine obtained on theDiels-Alder adduct obtaining the ROMP's monomers.

Synthesis of Benzyl-N,N-di-Boc-Guanidine 1

N, N′-Di-Boc-pyrazole-1-carboxamidine (11 mmol, 3.4 g) was added to around bottom flask and dissolved in methylene chloride. Triethylamine(9.3 mmol, 1.3 mL) and Benzylamine (9.3 mmol, 1.02 mL) were added to theflask and the reaction mixture was stirred for 16 hours at roomtemperature. The crude was diluted to 80 ml of methylene chloride andwashed with H₂O (2×100 mL), brine (1×100 mL), dried (MgSO₄ anhydrous)and filtered. The solvent was removed in vacuo and the crude waspurified by recrystallization using methylene chloride: MeOH, yielding2.0 g (63%) of compound 1 (Scheme 2).

Synthesis of Phenyl-Boc-Guanidine 2

Compound 2 was obtained following the same procedure described below,except for the heating of the reaction mixture at 50° C. The compound 2was purified by recrystallization in hot MeOH obtaining 892 mg (83%)(Scheme 3).

Synthesis of 2-Pyrimidyl-Boc-Guanidine 3

1,3-Bis(tert-butoxycarbonyl)-2-methyl-2-thiopseudourea (5.5 mmol, 1.6 g)and 2-amino-pyrimidine (8.3 mmol, 786 mg) were added to a round bottomflask and dissolved in methylene chloride. Then, Triethylamine (10.5mmol, 2.3 mL) was added to the stirring solution. The reaction wasplaced in an ice bath and stirred for 25 minutes (until reach 0° C.).Then, Mercury (II) Chloride (6.06 mmol, 1.65 g) was added, and thereaction was stirred for 48 hrs. The crude was filter through celite padand washed with H₂O (2×5 ml), brine (1×5 ml), dried (MgSO₄ anhydrous)and filtered. The crude was purified by column using n-hexane; ethylacetate (7:3), yielding 1.3 g (70%) of compound 3 (Scheme 4).

Synthesis of N-Boc-ethylenediamine 4

Ethylenediamine (1.0 mol, 66.6 mL) was added to a round bottom flaskcontaining 800 mL of methylene chloride (Scheme 5). Di-ter-butyldicarbonate anhydrous (0.15 mol, 32.7 g) were pre-mixed in 300 mL ofmethylene chloride and added dropwise to ethylenediamine solution. Thereaction was stirred for 16 hours, then, the organic phase was washedwith H₂O (2×800 mL), brine (1×800 mL), dried (MgSO₄ anhydrous) andfiltered. The solvent was removed in vacuo and a very light-yellowviscous liquid was obtained (78% yield) (Scheme 5).

Synthesis of Compound 5

N-Boc-ethylenediamine (39.2 mmol, 6.35 g) andexo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride (30.1 mmol,5 g) was added to a round bottom flask and dissolved in MeOH. Then,Triethylamine (72 mmol, 10 mL) was added, and the reaction mixture wasstirred at reflux for 20 hours. Compound 5 precipitated at roomtemperature and was purified by extraction on methylene chloride andrecrystallization using methylene chloride MeOH mixture. The solidobtained (62%) was deprotected using methylene chloride:trifluoraceticacid mixture (3:2). The solvent was removed in vacuo and the crude waspurified by precipitation in ether solution yielding pure compound 5(59%) (Scheme 6).

Synthesis of ROMP's monomers 6

Compound 5 (1.24 mmol, 400 mg) and benzyl-N, N-di-Boc-Guanidine (0.992mmol, 346.6 mg) were added to a round bottom flask and dissolved in THFand Triethylamine (7.44 mmol, 1 mL). The mixture was stirred at refluxfor 16 hours. Then, the solvent was removed in vacuo and the crude wasdiluted in methylene chloride and washed with NH₄Cl (1×10 mL), brine(1×10 mL), dried (MgSO₄ anhydrous) and concentrated in vacuo. The crudewas purified by flash column using n-Hexane:Ethyl Acetate (2×4:1) and(1×1:1) yielding monomer 6 (45%) (Scheme 7).

Synthesis of ROMP's Monomer 7

The compound 7 (Scheme 8) was synthesized using the same proceduredescribed below for compound 6. The crude was purified by flash columnusing n-Hexane:Ethyl Acetate (9:1) and then (4:1), yielding monomer 7(52%).

Synthesis of ROMP's Monomer 8

The compound 8 (Scheme 9) was synthesized using the same proceduredescribed below for compound 6. The crude was purified by flash columnusing Methylene Chloride:Ethyl Acetate (9:1), then (4:1), and finally(7:3), yielding monomer 7 (58%).

Synthesis of Monomers 13 and 14

Monomers 13 and 14 (Scheme 10) were used for polymerization andsynthesized. Briefly, synthesis of monomer 13 began with the N-Bocprotection of ethylenediamine with the addition of 0.1 equivalents ofdi-tert-butyl decarbonate dropwise overnight. N-Boc protectedethylenediamine was refluxed with Diels Alder adduct(exo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride) and wasprecipitated after reaction was complete, yielding compound 12. Thiscompound was deprotected using TFA (to arrive at compound 5) and thefree amine was converted to Boc-protected guanidine (to arrive atcompound 13). Compound 14 was synthesized by refluxing Diels Alderadduct (exo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride)with benzylamine.

N-Boc protected ethylenediamine: Yield: 83%. ¹H NMR (400 MHz, CDCl₃): δ5.44 (br s, 1H), 2.96 (s, 2H), 2.59 (t, 2H), 1.25 (s, 9H), 1.04 (s, 2H).Compound 12: Yield: 50%. ¹H NMR (400 MHz, CDCl₃): δ 6.51 (d, 2H), 5.25(d, 2H), 4.79 (br s, 1H), 3.62 (t, 2H), 3.29 (t, 2H), 2.84 (t, 2H), 1.41(s, 9H). Compound 5: Yield: 85%. ¹H NMR (400 MHz, DMSO-d₆): δ 7.98 (s,3H), 6.56 (s, 2H), 5.14 (s, 2H), 3.62 (t, 2H), 2.94 (m, 4H). Compound13: Yield: 68%. ¹H NMR (400 MHz, CDCl₃): δ 11.40 (s, 1H), 8.39 (s, 1H),6.48 (d, 2H), 5.23 (d, 2H), 3.67 (t, 2H), 3.60 (t, 2H), 2.84 (t, 2H),1.44 (m, 18H). Compound 14: Yield: 70%. ¹H NMR (400 MHz, CDCl₃): δ 7.30(m, 5H), 6.52 (s, 2H), 5.29 (s, 2H), 4.64 (s, 2H), 2.86 (s, 2H).

Synthesis of Polymers

N-Boc-N-(R)-Guanidyl Carbamoyl polymers were synthesized by dissolvingmonomer 6, 7 and 8 respectively in dry DCM and adding varying molarequivalents of Grubbs' 3^(rd) generation catalyst (Scheme 11). Thesolutions were stirred for 1 hour before the addition of 500 uL of ethylvinyl ether to terminate the polymerization. The polymer solutions wereprecipitated (3 times) into diethyl ether and precipitates werecollected and dried. An aliquot of each polymer was taken for GPC andNMR analysis. Finally, Boc-group on each polymer was removed using amixture of methylene chloride and trifluoro acetic acid. Afterdeprotection, deprotected polymers were precipitated (3 times) intodiethyl ether and precipitated were collected, dried, weighed anddissolved in DMSO.

Synthesis of G

Scheme 12a shows the synthesis of G. Monomer 13 was dissolved in DCM.Grubbs 3^(rd) generation catalyst was dissolved in DCM and added to thestirring monomer solution. After 60 min, the living polymer wasend-capped with 1 mL of ethyl vinyl ether. The polymer solution wasprecipitated into stirring diethyl ether (3×) and dried. The dried solidwas dissolved in a DCM/TFA mixture (1:1, v/v) and deprotected overnight.The reaction mixture was precipitated (3×) and collected viacentrifugation.

G protected: ¹H NMR (400 MHz, CDCl₃): δ 11.45 (br, 1H), 8.46 (br, 1H),6.06 (br, 1H), 5.73 (br, 1H), 4.98 (br, 1H), 4.48 (br, 1H), 3.65 (br,4H), 3.35 (br, 2H), 1.47 (d, 18H). G: ¹H NMR (400 MHz, DMSO-d6): δ 7.97(br, 1H), 7.42 (br, 4H), 5.97 (br, 1H), 5.76 (br, 1H), 4.94 (br, 1H),4.45 (br, 1H), 3.51 (br, 2H), 3.34 (br, 4H).

Synthesis of Ph-CG

Scheme 12a shows the synthesis of Ph-CG. G polymer was dissolved in dryDMF. 5 equivalents of phenyl isocyanate were added. The mixture wassealed in a vial and allowed to react overnight at 75° C. The reactionmixture was precipitated into diethyl ether (3×) and the polymer wascollected via centrifugation. Ph-CG: ¹H NMR (400 MHz, DMSO-d6): δ 7.94(br, 2H), 7.43 (br, 3H), 7.27 (br, 2H), 5.92 (br, 1H), 5.71 (br, 1H),4.87 (br, 1H), 4.42 (br, 2H), 3.41 (br, 6H).

Synthesis of Bz, PhPr, and PhBu-CG

As shown in Scheme 12b, protected G polymer was dissolved in THF towhich 2.5 equivalents of benzylamine, 3-Phenylpropylamine or4-Phenylbutylamine were added. The mixture was sealed in a vial andallowed to react overnight at 75° C. The reaction mixture wasprecipitated into diethyl ether (3×) and then deprotected in DCM/TFAmixture (1:1, v/v). Deprotected polymer solution was precipitated intodiethyl ether (3×) and polymer collected via centrifugation.

Bz-CG protected: ¹H NMR (400 MHz, CDCl₃): δ 12.04 (br, 1H), 8.14 (br,1H), 7.20 (br, 5H), 5.97 (br, 1H), 5.67 (br, 1H), 4.97 (br, 1H), 4.33(br, 4H), 3.56 (br, 4H), 3.17 (br, 2H), 1.44 (s, 9H). Bz-CG: ¹H NMR (400MHz, DMSO-d6): δ 9.15 (br, 1H), 8.61 (br, 2H), 7.99 (br, 1H), 7.27 (br,5H), 5.92 (br, 1H), 5.71 (br, 2H), 4.94 (br, 1H), 4.41 (br, 1H), 4.25(br, 4H), 3.75 (br, 4H). PhPr-CG protected: ¹H NMR (400 MHz, CDCl₃): δ12.10 (br, 1H), 8.13 (br, 1H), 7.27 (br, 2H), 7.21 (br, 3H), 5.98 (br,1H), 5.68 (br, 1H), 4.99 (br, 1H), 4.34 (br, 1H), 3.63 (br, 2H), 3.16(br, 4H), 2.60 (br, 2H), 1.77 (br, 2H), 1.40 (s, 9H). PhPr-CG: ¹H NMR(400 MHz, DMSO-d6): δ 9.18 (br, 1H), 8.14 (br, 2H), 7.94 (br, 1H), 7.21(br, 5H), 5.97 (br, 1H), 5.65 (br, 1H), 4.82 (br, 1H), 4.36 (br, 1H),3.64 (br, 2H), 3.18 (br, 4H), 2.58 (br, 2H), 1.76 (br, 2H). PhBu-CGprotected: ¹H NMR (400 MHz, CDCl₃): δ 12.08 (br, 1H), 8.08 (br, 1H),7.27 (br, 2H), 7.10 (br, 3H), 6.02 (br, 1H), 5.71 (br, 1H), 5.06 (br,1H), 4.34 (br, 1H), 3.66 (br, 2H), 3.14 (br, 4H), 2.59 (br, 2H), 1.60(br, 4H), 1.40 (s, 9H). PhBu-CG: ¹H NMR (400 MHz, DMSO-d6): δ 9.11 (br,1H), 8.08 (br, 2H), 7.90 (br, 1H), 7.16 (br, 5H), 6.05 (br, 1H), 5.74(br, 1H), 4.85 (br, 1H), 4.42 (br, 1H), 3.66 (br, 2H), 3.13 (br, 4H),2.62 (br, 2H), 1.60 (br, 4H).

Synthesis of Random-Bz-G

As shown in Scheme 12c, molar equivalents of monomer 13 and 14 weredissolved in DCM. Grubbs 3^(rd) generation catalyst was dissolved in DCMand added to the stirring monomer solution. After 60 min, the livingpolymer was end-capped with 1 mL of ethyl vinyl ether. The polymersolution was precipitated into stirring diethyl ether (3×) and dried.The dried solid was dissolved in a DCM/TFA mixture (1:1, v/v) anddeprotected overnight. The reaction mixture was precipitated (3×) andcollected via centrifugation.

Random-Bz-G protected: ¹H NMR (400 MHz, CDCl₃): δ 11.43 (br, 0.5H), 8.46(br, 0.5H), 7.27 (br, 2.5H), 6.04 (br, 1H), 5.75 (br, 1H), 4.99 (br,1H), 4.64 (br, 1H), 4.47 (br, 1H), 3.65 (br, 2H), 3.32 (br, 2H), 1.44(s, 9H). Random-PN-Bz-G: ¹H NMR (400 MHz, DMSO-d6): δ 7.73 (br, 1H),7.26 (br, 4H), 5.96 (br, 1H), 5.71 (br, 1H), 4.88 (br, 1H), 4.55 (br,1H), 4.41 (br, 1H), 3.47 (br, 2H), 3.33 (br, 2H).

Synthesis of Block-Bz-G

As shown in Scheme 12d, monomer 13 was dissolved in DCM. Grubbs 3^(rd)generation catalyst was dissolved in DCM and added to the stirringmonomer solution. After 15 mins, monomer 14 solution was added to thestirring polymerization solution and allowed to stir for additional 45mins. Afterwards, the living polymer was end-capped with 1 mL of ethylvinyl ether. The polymer solution was precipitated into stirring diethylether (3×) and dried. The dried solid was dissolved in a DCM/TFA mixture(1:1, v/v) and deprotected overnight. The reaction mixture wasprecipitated (3×) and collected via centrifugation.

Block-Bz-G protected: ¹H NMR (400 MHz, CDCl₃): δ 11.41 (br, 0.5H), 8.47(br, 0.5H), 7.30 (br, 2.5H), 6.00 (br, 1H), 5.68 (br, 1H), 5.04 (br,1H), 4.56 (br, 1H), 4.42 (br, 1H), 3.68 (br, 2H), 3.28 (br, 2H), 1.46(s, 9H). Block-Bz-G: ¹H NMR (400 MHz, DMSO-d6): δ 7.91 (br, 0.5H), 7.44(br, 2H), 7.23 (br, 2.5H), 5.96 (br, 1H), 5.72 (br, 1H), 4.94 (br, 1H),4.51 (br, 1H), 4.45 (br, 1H), 3.46 (br, 2H), 3.35 (br, 2H).

Molecular Weight Determination

Aliquots of polymer solutions in tetrahydrofuran (THF) ordichloromethane (DCM) were diluted in 1 mL of HPLC-grade THF andfiltered through a 0.45 μm polytetrafluoroethylene (PTFE) syringe filterprior to injection.

Measurement of Hydrodynamic Diameters and Zeta Potential

Nanoparticle tracking analysis (NTA) was used to determine thehydrodynamic diameter (HD) of PN/protein complexes. Briefly, 1 mL ofPN/BSA complexes with final concentrations of 10 μM/100 nM were preparedby mixing equal volumes of polymer and BSA substock solutions,incubating for 30 minutes and diluting in PBS to a final volume of 1 mL.1 mL of this solution was then injected into the NTA chamber and videosof the scattering particles was recorded for 30 seconds. The softwareidentified each individual particle and tracked its motion, relating theparticle displacement as a function of Brownian motion, which relates tothe particle size through the Stokes-Einstein equation. Theconcentrations of samples were chosen to meet the manufacturers'recommendation of 20-100 particles per frame and a concentration of10⁷-10⁹ particles/mL. All measurements were performed in triplicate at25° C. One representative HD plot was selected for Ph-CG/BSA complex (10μM/100 nM), demonstrating the formation of monodisperse nanoparticles.Zeta Potential was acquired by preparing samples in the same way as forNTA prior to analysis.

pKa Determination

pKa was determined for the different PNs by titrating 2 mM polymersolution in 1 mL of acidified (pH˜3) 100 mM NaCl solution and titratingto pH 11 with 5 μL increments of a 25 mM KOH solution. For thetitration, the pH was determined using a Mettler Toledo InLabUltra-Micro pH Probe. pKa value for each polymer was determined byplotting the ΔpH/volume of KOH (FIG. 3A) and identifying the largestΔpH. For polymers with two maxima, the volume of the median pointbetween the two maxima was chosen as the point where pH=pKa. Forrandom-Bz-G (FIG. 3C) and block-Bz-G, no deprotonation of the cationicmoiety occurs and therefore titration curves are only representative ofthe change in pH of solution.

Fluorescent Quenching Titration

The complexation between the PNs and protein was studied by monitoringthe fluorescence emission intensity (Ex: 540 nm; Em: 576 nm) ofrhodamine-labelled bovine serum albumin (Rho-BSA) as a functional ofincreasing concentrations of PNs. Rhodamine quenching was indicative ofprotein binding. Briefly, polymer solutions in DMSO were seriallydiluted in DMSO and further diluted in H₂O. Emission of Rho-BSAsolutions was taken before and after the addition of polymer solutions,and the relative emission intensity as a function of polymerconcentration was plotted. Final concentration of Rho-BSA was 100 nM andof polymers ranged from 32-0.5 μM.

Dissociation Constant Determination

The dissociation constant was determined by converting the relativefluorescence quenching plots to fractional saturation plots usingequation 1 below:

$\begin{matrix}{{{Fractional}{{Saturation}(y)}} = \frac{F_{P} - F_{0}}{F_{sat} - F_{0}}} & (1)\end{matrix}$

-   -   where F₀, F_(P), and F_(sat) were the relative emission        intensities of Rho-BSA only, polymer/Rho-BSA complexes at the        various concentrations tested, and polymer/Rho-BSA at        saturation. The dissociation constant was determined by equation        2 below:

$\begin{matrix}{y = \frac{( {P + c + K_{d}} ) - \sqrt{( {P + c + K_{d}} )^{2} - {4{Pc}}}}{4c}} & (2)\end{matrix}$

-   -   where y is the fractional saturation plot obtained with equation        1, P is the polymer concentration (x-axis) and c is the constant        Rho-BSA concentration (100 nM). K_(d) was determined using the        non-linear curve fitting module of Origin 8.5 and equation 2.        Serum Stability Assay

The stability of complexes in the presence of 10% fetal bovine serum(FBS) was studied by monitoring the fluorescence of PN/Rho-BSA complexesover 2 hours. Briefly, 40 μL of complexes were prepared by mixing equalvolumes of polymer and Rho-BSA solutions and allowing them to complexfor 30 m. These complexes were then diluted into 360 μL of either PBS orPBS with 10% FBS and the emission spectra was recorded immediately. Thecomplexes were allowed to sit at room temperature between readings.

Cell Culture

HeLa cells were cultured in Gibco DMEM High Glucose medium supplementedwith 10% (v/v) FBS and 1% (v/v) Penicillin-Streptomycin mixture. Adiposederived mesenchymal stem cells and T cells were a kind gift from Dr.Robert Sackstein at Florida International University. MSCs were culturedin DMEM high glucose medium supplemented with 10% FBS and then treatedwith PN/R-PE. T cells were cultured in RPMI supplemented with 10% FBSand then treated with PN/R-PE.

PN Toxicity Assay

HeLa cells were seeded in a 96-well plate (˜10,000/well) in 200 μL ofcomplete medium and allowed to attach for one day at 37° C. under ahumidified atmosphere of 5% CO₂ prior to sample treatment. Finalconcentrations of 40, 20, 10, and 5 μM were added into the completemedia by dilution of the polymer stock solutions. After addition of thesamples, cells were incubated for 18 h prior to treatment with 10 μL ofmethylthiazole tetrazolium (MTT) (5 mg/mL in PBS) and incubated for 4 hat 37° C. After incubation, 200 μL of medium was gently removed and 100μL of biological grade DMSO was added to solubilize the purple formazancrystals. Absorbance was measured by microwell plate reader. Cellviability was determined as a function of absorbance of each samplerelative to control wells. All measurements represent the average ofthree independent measurements+/−standard deviation.

Flow Cytometry Analysis

Hela cells and MSCs were seeded into 12 or 6-well plates (˜100,000/wellor 60,000/well, respectively) in complete media and allowed to attachfor one day at 37° C. under a humidified atmosphere of 5% CO₂ prior tosample treatment. In contrast, T-cells were counted plated in 12-wellplates (˜400,000/well) in complete RPMI media and treated right away.R-PE, EGFP, FITC-BSA, and Rho-BSA stock solutions were diluted toworking concentrations with 1×PBS. Polymer stock solutions were preparedat 1 mM in DMSO. 40 μL of polymer/protein complexes were prepared bymixing appropriate volumes of polymer and protein substock solutions andincubating for 30 m at room temperature in the dark. Complexes wereadded dropwise to each well to the cells in complete media and incubatedfor varying periods of time, depending on the experiment. After theincubation periods required, adherent cells were rinsed three times withfull volumes of PBS, followed by washing with 1 μM heparan sulfatesolution to remove any extracellular surface-bound complexes. The cellswere harvested with TrypLE, transferred to centrifuge tubes, rinsed anadditional three times with PBS before being finally resuspended in 300μL of PBS. In the case of suspension cells, cells were transferred tocentrifuge tubes, centrifuged and resuspended in PBS three times. Cellswere analyzed by flow cytometry, in which data for 10,000 events werecollected. Analysis for primary cells were performed with supervisionand technical assistance of Dr. Sackstein group.

Cellular Entry Pathway

In order to study the mechanism of uptake, HeLa cells were treated withPh-CG/R-PE complexes (10 μM/15 nM) for 1 h under energy-independentconditions or under pre-treatment with various pharmacologicalinhibitors. Briefly, HeLa cells seeded the day prior to sample treatmentin 12-well plates (100,000/well). The day of experiment, cells wereequilibrated for 30 minutes under 4° C., ATP depletion conditions (NaN₃:10 mM & 2-deoxyglucose: 50 mM), chlorpromazine (28 μM), LYS 294003 (3μM), Cytochalastin D (10 μM), methyl-B-cyclodextrin (1 mM) and genistein(200 μM) or normal culture conditions. Complexes were added dropwise,and cells were incubated for 1 h prior to analysis via flow cytometry asdescribed previously.

Functional Protein Delivery

MTT assay was performed with PN/enzyme complexes are describedpreviously. In short, serial dilutions of saporin or RNase were preparedand complexes with various PNs. For serum-containing media, complexeswere added to HeLa cells and incubated overnight prior to MTT treatment.For serum-free experiments, complexes were added in DMEM for 4 h and themedia was replaced with complete media overnight prior to MTT treatment.

Confocal Imaging

Hela cells were seeded on 12-well plates (˜60,000/well) containing glasscoverslips one day before sample treatment. Complexes were prepared asdescribed previously. After incubation for varying periods of time usingsame culture conditions discussed earlier, the medium was removed, andcells were washed three times with PBS and once with heparan sulfate.Cells were fixed with 4% PFA for 10 minutes and rinsed once with PBS.Nuclei were stained with Hoechst 33342 at final concentration of 1 μg/mLfor 7 minutes. For cells with Lysotracker Red staining, themanufacturers protocol was followed. The coverslips were mounted onmicroscope slides using 1:1 glycerol/PBS mounting medium.

Example 1—Characterizations of PNs and PN/BSA Complexes

After synthesizing a guanidine containing poly(oxanorbornene imide) (G,FIG. 1 ), phenyl isocyanate was reacted with guanidine to synthesize thePh-CG containing PN. Synthesis of Bz, PhPr, and PhBu was done via thereaction of the respective primary amines and the N,N′-di-boc-guanidinecontaining PN. Random and block copolymers with repeating units bearingboth guanidine and aromatic benzyl side chains (random-Bz-G andblock-Bz-G) were also synthesized as control PNs (Schemes 10 and 12).

Complexation was achieved by mixing the corresponding PN and protein inan aqueous solution. Nanoparticle tracking analysis and zeta potentialmeasurements indicate that all PNs form relatively uniform nanometersize complexes with slightly negative zeta potentials (FIG. 2 ), despitethe excess amounts of PNs used in the complex (Tables 1 and 2).

TABLE 1 Summary of molecular weights (M_(n) and M_(w), kDa) and acidityconstant (pKa) of polymers and the hydrodynamic diameters (HD, nm), zetapotentials (ζ), and dissociation constants (K_(d), μM) of PN/BSAcomplexes. PNs M_(n) M_(w) HD^([a]) ζ^([a]) K_(d) ^([b]) pK_(a) ^([c]) G4.8 5.4 NA NA NA NA Ph-CG 5.5 5.9 200 ± 55 −14.3 3.7 ± 0.8 6.1 Bz-CG 5.76.1 179 ± 31 −15.3 3.8 ± 0.6 6.1 random-Bz-G 5.0 5.6 230 ± 50 −8.9 3.3 ±0.6 NA block-Bz-G 4.5 5.1 178 ± 45 −6.1 5.3 ± 1.3 NA^([a])Concentrations of polymer and BSA in the complexes were 10 μM and100 nM, respectively. ^([b])Dissociation constants were calculated usingrhodamine labelled BSA. ^([c])Effective pK_(a) was determined by pHtitration. NA: Not able to determine under the titration condition.

TABLE 2 Summary of molecular weights (M_(n) and M_(w), kDa) and acidityconstant (pKa) of polymers and the hydrodynamic diameters (HD, nm), zetapotentials (ζ), and dissociation constants (K_(d), μM) of PN/BSAcomplexes. PNs M_(n) M_(w) HD^([a]) ζ^([a]) K_(d) ^([b]) pK_(a) ^([c])PhPr-CG 5.7 6.1 168 ± 44 −11.6 3.1 ± 0.4 6.3 PhBu-CG 5.7 6.1 175 ± 36−13.4 5.7 ± 1.2 6.1 random-Bz-G (10 k) 10.3 11.4 208 ± 54 −11.9 — NAblock-Bz-G (10 k) 8.9 10.3 209 ± 48 −14.5 — NA ^([a])Concentrations ofpolymer and BSA in the complexes were 10 μM and 100 nM, respectively.^([b])Dissociation constants were calculated using rhodamine labelledBSA. ^([c])Effective pK_(a) was determined by pH titration. NA: Not ableto determine under the titration condition.

Considering the negatively charged bovine serum albumin (BSA) in neutralpH, the negative zeta potentials of PN/BSA complexes suggest thepossible neutral (or slightly positive) charge of PNs, especially forPh-CG. The acylation on guanidine results in a sharp pKa decrease from12-13 to −8. The pKa values of CG derivatives were measured as ˜6.1using the pH titration method (FIG. 3 ). Therefore, Ph-CG exists asneutral in the physiological environment.

Fluorescence quenching assays using rhodamine-labeled BSA (Rho-BSA)confirm the high protein affinity of Ph-CG. The fluorescence intensityof Rho-BSA will be decreased as the Rho-BSA concentration increases inthe complex due to self-quenching. By monitoring the fluorescencequenching of Rho-BSA as a function of PN concentrations, thedissociation constants (K_(d)) of PN/BSA complexes were determined as−3-5 μM (FIGS. 4 and 5 ). Despite very similar K_(d) values, the complexstability in phosphate buffered saline (PBS) containing 10% fetal bovineserum (FBS) is significantly different depending on the functionalgroup. While the Ph-CG/protein complex exhibits the same fluorescenceintensity to that of the initial complex, the random-Bz-G/proteincomplex shows a slight increase in the intensity within the 2 h ofincubation in a serum free medium (FIGS. 6A-6B). In the presence ofserum, the Ph-CG/complex exhibits no fluorescence changes over theincubation time (FIG. 6A), indicating the complex stability was notcompromised by the serum proteins. Meanwhile, the fluorescence intensityof random-Bz-G/protein complex was sharply increased within 10 min ofincubation (FIG. 6B), suggesting the substantial complex dissociation.Another CbmG derivative, Bz-CG, also exhibits excellent serum stabilitysimilarly to Ph-CG (FIG. 7 ).

Considering the similar physical properties of the PN/protein complexes,this substantial serum stability difference between CbmG- andconventional guanidine-containing PNs is due to enhanced HB interactionsof CbmG resulted from low pKa value and attached hydrophobicity.

Example 2—Cellular Delivery Efficiencies

All PNs exhibited no noticeable cell viability inhibition up to 40 mM,except the guanidine containing PN (G) that showed a slight viabilityinhibition (˜15%) at that concentration (FIG. 8 ).

Using flow cytometry, the cellular protein delivery efficiencies of PNswere evaluated by measuring the median fluorescent intensity (MFI) ofHeLa cells incubated with PNs/red algae-phycoerythrin (R-PE) complexesin a serum-containing medium overnight. As shown in FIG. 9 , Ph-CG withmolecular weight (MW) of ˜5,000 g/mol exhibits about 5- and 300-foldhigher MFI than the control random-Bz-G and the commercially availablePULSin reagent, respectively, despite all PN/R-PE treated cells beingR-Pe positive.

Structurally, the hydrophobic phenyl group is directly introduced toguanidine via the Cbm extension in Ph-CG, whereas the charges andhydrophobic groups in the control PNs are segregated in either random orblock backbone structures. The control PNs with doubled MWs, in whichthe PNs have the same numbers of guanidine and hydrophobic unit perrepeating unit to those of Ph-CG, exhibit no improved deliveryefficiency. It is interesting to observe that the R-PE deliveryefficiency decreases exponentially as the chain length between Ph and CGincreases (FIG. 9 ). The separation of the phenyl ring by 1 carbon unit(i.e., Bz-CG) decreases the protein uptake efficiency by ˜75% and afurther increase in the distance (i.e., PhPr and PhBu) eventually leadsto minimal delivery.

Considering very similar pKa, fluorescence quenching behaviours, andcomplex serum stability among the CG derivatives, it is believed thatthe coplanarity of Ph-CG contributes to better cellular entry throughbetter interactions with the membranes, resulting in high proteindelivery efficiency. While the Ph group maintains the coplanarity withCG through p-electron conjugation in Ph-CG and thus the rigidity of theactive group is maintained, no coplanarity is present when the phenylgroup is connected to Cbm through methylene spacers because of freerotation of the methylene group.

Example 3—Cellular Delivery Using Ph-CG

The robust design concept of Ph-CG for universal protein delivery wasexamined by treating primary human mesenchymal stem cells (MSC) and CD4+T cells, respectively, with Ph-CG/fluorescent proteins (FPs) in serumcontaining media. As shown in FIG. 10 , Ph-CG efficiently deliversvarious FPs with different sizes and surface properties tohard-to-transfect cells with greater than 80% of the FP positive cellpopulations.

Interestingly, Rho-BSA delivery efficiency was generally lower than thatof the intrinsic FPs. It is speculated that the altered surfacefunctionalities from chemical conjugations of Rho to BSA could beresponsible for the relatively low delivery efficiency. For thosenon-FPs with smaller size (e.g., 13.7 kDa RNase A) and positivelycharged surfaces [i.e., RNase (pI 8.6) and Saporin (pI 9.3)], functionalassays were used to validate Ph-CG-mediated delivery in a serumcontaining medium.

Cellular entry pathway studies indicate that the internalization of thePh-CG/R-PE complex primarily occurs via energy dependent pathway (FIG.11 ). Ph-CG/R-Pe entry was decreased under the pretreatment of variouspharmacological endocytosis inhibitors, implying that those relativelywell-studied endocytosis pathways (i.e., clathrin-mediated endocytosisand macropinocytosis) are also involved in Ph-CG/FPs entry to HeLacells.

Example 4-pH-CG for Functional Enzyme Delivery

Saporin is a ribosome inactivating protein that irreversibly blocks thesynthesis of proteins in cells. RNase A is capable of degrading RNAchains and thus exhibiting toxic effects. While both cell membraneimpermeable enzymes show no toxicity on HeLa cells, an exponential cellviability inhibition was observed when Saporin (32.8 kDa) was deliveredby Ph-CG at less than 0.03 mg (FIGS. 12A-12B). It is noteworthy thatthis functional enzyme delivery was conducted in a serum containingmedium and the efficiency is very similar regardless of the serum. Thepositive controls exhibit poor enzyme activities in the presence ofserum, similarly to most of the reported systems.

Delivered RNase by Ph-CG also shows concentration-dependent exponentialcell viability decrease (FIGS. 13A-13B). However, RNase delivery wasmore efficient in a serum free medium, indicating that Ph-CG worksbetter with larger proteins than RNase. Nevertheless, this viabilityinhibition result indicates that internalized proteins possibly escapefrom endosomes and/or use different pathways (e.g., via leakymacropinosomes in micropinocytosis) to reach the cytosolic targets.

Example 5—Ph-CG for FITC-BSA Delivery

Confocal microscopic images of HeLa cells treated with Ph-CG/fluoresceinisothiocyanate (FITC) labeled-BSA show a diffused but intense cytosolicstaining pattern that is quite different from the characteristic puncta(FIGS. 14A-14D and FIGS. 15A-15C for other FPs).

To determine whether FITC-BSA delivered by Ph-CG and random-Bz-G,respectively, are localized in acidic endosome/lysosome, cells werecounter stained with Lysotracker Red, and quantitatively analyzed thelevels of overlap between green and red colors using the Pearson'scorrelation coefficient (PCC) method. Low PCC scores of 0.17 and 0.25were calculated from cells treated for 1 h with Ph-CG and random-Bz-G,respectively, indicating FITC-BSAs are not in acidic organelles.

When the treatment time increased to 18 h, the PCC score from thecontrol random-Bz-G treated cells increased substantially (i.e., 0.68),indicating high FITC-BSAs localization in the endosome/lysosome.Meanwhile, the low PCC score (0.32) of 18 h Ph-CG/FITC-BSA treated cellsindicates that the location of FITC-BSA is not in acidic organelles.

Example 6—Cellular Delivery Using Carbamoylated Derivatives of Guanidine

PNs such as carbamoylguanidinybenzene (CGB) andcarbamoylguanidinypyrimidine (CGP) were synthesized for intracellularprotein delivery. To investigate the delivery of R-PE, a large (240 kDa)fluorescent protein, into HeLa cells, polymers were mixed with R-PE andallowed to self-assemble into nanoparticles for 30 minutes prior totreatment to cells. HeLa cells were incubated in the presence ofcomplexes overnight prior to thorough rinsing and flow cytometricanalysis. As seen in FIG. 16A, GCB achieved 3-5 folds improved R-PEdelivery compared to a constitutional isomer CGB, at all tested ratios.Additionally, GCB was able to transfect the entire cell population,achieving 100% R-PE positive cells at all concentrations, while CGBrequired higher concentrations of PN. As seen in FIG. 17 , confocalimaging of HeLa cells treated with PN/EGFP complexes show a diffusegreen signal distributed around the cytosol.

Example 7—Additional Derivatives

Thiourea and selenourea derivatives of GCB and CGB may also besynthesized using appropriated reagents. For example, compound 15 can besynthesized from compound 5 and carbon disulfide (Scheme 13). Thethiourea GCB and CGB may be synthesized from, for example, compound 15and 1-phenylguanidine or 1-benzylguanidine. Selenourea monomer may besynthesized using2,4-bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide,[PhP(Se)(μ-Se)]₂ (Scheme 14).

All patents and publications referred to or cited herein areincorporated by reference in their entirety, including all figures andtables, to the extent they are not inconsistent with the explicitteachings of this specification.

It should be understood that the examples and embodiments describedherein are for illustrative purposes only and that various modificationsor changes in light thereof will be suggested to persons skilled in theart and are to be included within the spirit and purview of thisapplication.

We claim:
 1. A polymeric system comprising

 wherein

 represents a backbone of a polymer, polysaccharide, protein, peptide,antibody, nucleic acid, metal organic framework or a nanoparticle; n≥1;W is S, O or Se; X is a linker, the linker being a C1-C20 alkylene,alkoxylene or heteroalkylene; Y and Y′ are each independently selectedfrom hydrogen, alkyl, substituted alkyl, aryl, substituted aryl,heteroalkyl, substituted heteroalkyl, heteroaryl, substitutedheteroaryl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl,substituted heterocycloalkyl, cycloalkenyl, substituted cycloalkenyl,alkenyl, substituted alkenyl, alkynyl, alkoxy, substituted alkoxy,hydroxyl, haloalkyl, amino, acyl, alkylamino, arylamino andhydroxylalkyl.
 2. The polymeric system according to claim 1, thepolymeric system comprising

wherein R′ is selected from hydrogen, halogen, alkyl, substituted alkyl,aryl, substituted aryl, heteroalkyl, substituted heteroalkyl,heteroaryl, substituted heteroaryl, cycloalkyl, substituted cycloalkyl,heterocycloalkyl, substituted heterocycloalkyl, cycloalkenyl,substituted cycloalkenyl, alkenyl, substituted alkenyl, alkynyl, alkoxy,substituted alkoxy, amino, haloalkyl, hydroxyl, acyl, alkylamino,arylamino and hydroxylalkyl.
 3. A composition comprising the polymericsystem according to claim 1, a therapeutic agent and a pharmaceuticallyacceptable carrier.
 4. The polymeric system of claim 1, wherein

represents the backbone of a polymer.
 5. The polymeric system of claim4, the polymer being amine functionalized polymethacrylates orpolyacrylates, branched or linear polyehtyleneimines, polyamidoamine,amine functionalized dendrimers, poly-L-lysine, chitosan, aminefunctionalized dextran, amine functionalized alginates, aminefunctionalized heparin, or amine functionalized oligo or polysaccharide.6. The polymeric system of claim 5, the polymer being poly-L-lysine. 7.The polymeric system of claim 1, X being C1-C10 heteroalkylene.
 8. Thepolymeric system of claim 7, X being —(CH₂CH₂O-)n-, wherein n=1-100. 9.The polymeric system of claim 1, Y and Y′ each independently beingselected from phenyl (Ph), benzyl (Bz), phenylpropyl (PhPr), phenylbutyl(PhBu), hexylamine (HA), benzylamine (BA), and aminoethoxyethanol (AEE).10. The polymeric system of claim 1, Y and Y′ each independently beingselected from

 each Z being C or N.
 11. The polymeric system of claim 1, comprising

 being poly-L-lysine; W is O; X is —(CH₂CH₂O—)n-, wherein n=2; and Y isPh.
 12. A composition comprising the polymeric system of claim 1.